Prognostic Value of a Structural Brain MRI Score in the Acute Phase of Aneurysmal Subarachnoid Hemorrhage: A Pilot Study

Background/objective: Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high morbidity and mortality despite advances in management. We evaluated the prognostic significance of a qualitative score using brain magnetic resonance imaging (MRI) features obtained early after aSAH.

Methods: Patients with aSAH were enrolled in a prospective observational cohort and underwent brain MRI during their acute hospitalization. MRIs were rated using a scoring system that considers the anatomical location of signal intensity changes on diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) sequences. The relationship between MRI scores and functional outcome defined by modified Rankin scale (mRS) at 6 months was evaluated in uni- and multivariable models.

Results: The cohort included 45 aSAH patients (median World Federation of Neurologic Surgeons (IQR) 2 (1-4)) who underwent brain MRI a mean (SD) of 9.0 ± 8.0 days after aSAH. At 6 months after aSAH, 26 patients had achieved a favorable outcome (mRS ≤ 2) while 15 had an unfavorable outcome (mRS > 2). Deep gray nuclei (DGN) score (p = 0.016), cortex + DGN score (p = 0.015), FLAIR score (p = 0.016), DWI score (p = 0.0045), and overall score (p = 0.0081) were significantly lower in patients with favorable outcome compared to those with unfavorable outcome. However, MRI scores were not independent predictors of outcome in multivariable models adjusting for admission Hunt and Hess, Glasgow Coma Scale, or World Federation of Neurologic Surgeons scales.

Conclusions: In this pilot study, a qualitative scoring system using anatomically defined MRI FLAIR and DWI signal abnormalities identified in the acute phase of aSAH was linked to 6-month functional outcome. However, these scores did not add prognostic value to established indices of neurological severity.